Patent application title: Ozonated capacitive deionization process

Abstract:

Water from coal bed methane production which is suitable for almost
nothing, is ozonated in a reactor to oxidize the iron content from +2 to
+3, that is from ferrous to ferric, and to oxidize the manganese content
from +2 to +4. The water after such first treatment is run through a
separation means and then through a rotating filter, and then subjected
to capacitive deionization, to yield clean water, which is then treated
further to adjust he sodium content to render the water suitable for
domestic and agricultural purposes. Some of the produced water is run
back through the capacitive deionization cells when no voltage is applied
to clean the cells for the next voltage application cycle. Some of the
water produced may also be run back through the separation means to help
clean out the crud.

Claims:

1. A process for producing pure water for agricultural and domestic
purposes from coal bed methane derived water, which process comprises:a)
delivering CBM production water to a reaction chamber,b) introducing
ozone into the reaction chamber,c) reacting the ozone with the CBM
production water, to oxidize metal ions therein,d) delivering the
ozonated CBM water to a separation means,e) filtering the liquid output
from the separation means, and removing the oxidized metallic ions and
compounds,f) filtering the water from the separation means,g) delivering
the filtered water to at least one capacitive desalination cell for
treatment,h) activating the at least one desalination cell to produce
desalinated water,i) delivering the product water from the at least one
desalination cell to a S.A.R. tank for further sodium content reduction.

2. The process of claim 1 wherein the reaction chamber is a Mazzei®
injector.

3. The process of claim 1 wherein the filtering step comprises passing the
water from step e) through a rotating screen filter.

4. The process of claim 3 further including the step of removing the
separated out solids from the rotating screen filter.

5. The process of claim 1 further including the step of recycling some of
the output from the at least capacitive desalination cell back through a
valve system into the at least one desalination cell for cell cleaning
purposes.

6. The process of claim 1 further including the step of recycling some of
the output from the S.A.R. tank back through a valve system into the at
least one desalination cell for cell cleaning purposes.

7. The process of claim 1 further including the step of recycling some of
the output from both the at least one capacitive desalination cell and
some of the output from the S.A.R. tank, back a valve system into the at
least one desalination cell for cell cleaning purposes.

8. The process of claim 1 wherein the separation means of step d) is a
sedimentation tank.

9. The process of claim 1 wherein the separation means of step d) is a
cyclonic separator.

10. The process of claim 1 wherein the separation means of step d) is a
Couette reactor/separator.

11. Desalinated water prepared by the process of claim 1.

12. Desalinated water prepared by the process of claim 3.

13. A process for producing pure water for agricultural and domestic
purposes from coal bed methane derived water, which process comprises:a)
delivering CBM production water to a reaction chamber which is a Mazzei
injector,b) introducing ozone into the reaction chamber,c) reacting the
ozone with the CBM production water, to oxidize metal ions therein,d)
delivering the ozonated CBM water to a separation means,e) filtering the
liquid output from the separation means, and removing the oxidized
metallic ions and compounds,f) filtering the water from the separation
means, wherein the filtering step comprises passing the water from step
e) through a rotating screen filter,g) delivering the filtered water to
at least one capacitive desalination cell for treatment,h) activating the
at least one desalination cell to produce desalinated water,i) delivering
the product water from the at least one desalination cell to a S,A,R,
tank for further sodium content reduction

14. The process of claim 13 further including the step of recycling some
of the output from the S.A.R. tank back through a valve system into the
at least one desalination cell for cell cleaning purposes.

15. The process of claim 13 wherein the separation means of step d) is a
Couette reactor/separator.

16. Desalinated water prepared by the process of claim 13.

Description:

RELATIONSHIP TO OTHER PATENT APPLICATIONS

[0001]This application is a divisional application of U.S. Ser. No.
12/454010, filed May 12, 2009, now U.S. Pat. No. ______.

FIELD OF INVENTION

[0002]This patent pertains to a process for ozonating and deionizing a
specific source of water to yield potable water for drinking and
agricultural purposes.

BACKGROUND OF THE INVENTION

[0003]Capacitive DEIONIZATION is not new, yet it has not had a huge
commercial success due to the high cost of implementation. Another reason
for the lack of commercial success is the historical problem of
contamination of capacitive deionization units by organic compounds and
high ionic loads both of which are alleviated by the ozonation and
separation steps prior to the capacitive deionization. When these
problems are eliminated, one obtains longer useful life for the
equipment, reduced power consumption, and faster regeneration of the CD
unit. The grandfather patent in the field is Farmer, U.S. Pat. No.
5,425,858 issued Jun. 20, 1995 to Joseph Farmer of Lawrence Livermore
Laboratory, which patent is assigned to the Regents of the University of
California. It is titled "Method and apparatus for capacitive
deionization, electrochemical purification and regeneration of
electrodes."

[0004]It is well known throughout California and other parts of the
western USA that obtaining reliable and plentiful supply of clean water
is becoming more and more difficult, especially in, view of the recent
drought years of 2006 and 2007 winters. Not only in the USA but in
Africa, Australia and the middle east, there are huge water availability
problems. For this reason Israel a little country has become a big player
in the water desalination industry.

[0005]CDT Systems of Dallas Tex. has licensed the aforementioned Farmer
patent as well as other Lawrence Livermore patents pertaining to the
impregnation of a carbon paper support with a
water-resorcinol-formaldehyde solution, and then polymerizing the
resorcinol formaldehyde resin, extracting the water, and then heating the
polymerized resin/paper structure to convert the resin to a micro porous
carbon aerogel supported on the paper. While the original process was and
still remains costly, CDT has achieved significant reductions in cost to
permit wider adoption of the capacitive deionization process using carbon
aerogels in specialized situations.

[0006]It is also known to the art that high sodium ion content is
detrimental to agriculture. The NaCl content when high affects the
permeability of the soil by rain or other irrigation water. Sodium when
present in soil tends to replace calcium and magnesium according to the
periodic table from the soil and the sodium causes dispersion of soil
particles thus reducing the ease of cultivation and permeability of the
soil to permit moisture to seep down to plant roots. The soil becomes
hard and compact. Other known problems caused by excess sodium in
irrigation water include formation of crusted seed beds, short term
saturation of the surface soil, while water fails to sink down to root
hairs. The pH goes up and this may be bothersome or evenly deadly to some
plants.

[0007]In the USA, Australia and England and other countries, there is much
coal produced, most of which is used for power generation. Coal bed
methane exists in areas where the dominant chemistry of the water in a
coal seam is sodium bicarbonate and where the coal seam is buried deeply
enough to maintain sufficient water pressure to hold the gas in place.
Since Coal Bed Methane hereinafter CBM travels with ground water in coal
seams, extraction of CBM for commercial use involves pumping available
water from the seam in order to reduce the water pressure that holds gas
in the seam. CBM has very low solubility in water and readily separates
as pressure decreases, allowing it to be piped out of the well separately
from the water. Water moving from the coal seam to the well bore
encourages gas migration toward the well. But the capture of this methane
gas creates a lot of water that is unsuitable for agriculture or other
domestic uses. This water which is known as coal bed methane gas water,
is also known by the term, PRODUCED WATER, and it must be purified before
it can used. CBM water also contains a high amount of salinity, and since
people don't like the taste of salt water, even if the water is pure from
microbes and other toxics, the salt content must be reduced or
eliminated. Not only is the high sodium content a taste problem, it is
also a health problem when ingested in large quantities. Salt water's
only domestic use is as a gargle, for sore throats But this is more than
a taste issue, it is a health issue. Soil destruction also takes place
due to the SAR effect.

[0008]But why is this purified high salinity water unsuitable for
agricultural purposes?

[0009]Salinity becomes a problem when enough salts accumulate in the root
zone to negatively affect plant growth. Excess salts in the root zone
hinder plant roots from withdrawing water from surrounding soil. This
lowers the amount of water available to the plant, regardless of the
amount of water actually in the root zone. For example, when plant growth
is compared in two identical soils with the same moisture levels, one
soil receiving salty water and the other receiving salt-free water,
plants are able to use more water from the soil receiving salt-free
water. Although the water is not held tighter to the soil in saline
environments, the presence of salt in the water causes plants to exert
more energy extracting water from the soil. The main point is that excess
salinity in soil water can decrease plant available water and cause plant
stress.

[0010]One very specific application of the process of this invention
relates to the generation of water suitable for both domestic and
agricultural purposes from coal bed methane gas water by a specialized
form of capacitive deionization followed by possible further treatment to
reduce the salinity. Not only is the water ultimately produced by this
process suitable for agriculture but it is suitable for human consumption
as well.

SUMMARY OF THE INVENTION

[0011]Coal bed methane [CBM] containing water, which is suitable for
almost nothing as produced from coal seams as a result of CBM extraction,
is collected, is then ozonated in a reactor to reduce organic content,
oxidize the iron content from +2 to +3, that is ferrous to ferric, and to
oxidize the manganese content from +2 to +4, that is manganous to
manganic. The water after such first treatment, which still contains
dissolved sodium and other ions is run through a reactor/separator, then
through a filtration step, and then is subjected to capacitive
deionization, to yield clean water, which then may be treated further to
adjust the sodium content to render the water suitable for domestic and
agricultural purposes. For economic reasons, it is suggested that the
water purification system of this invention be operated near the CBM
extraction facility.

[0012]It is an object therefore to provide a process for ozonating coal
bed methane produced water.

[0013]It is a second object to provide a mode of treating water formerly
having a content of Fe and manganese in their higher oxidation states,
separated and filtered, prior to being subjected to capacitive
deionization.

[0014]It is a third object to adjust the salt content, IE. the NaCl
content to render such water potable and suitable for agriculture.

[0015]Other objects of the invention will in part be obvious and will in
part appear hereinafter. The invention accordingly comprises the process
possessing the series of steps, and combination of elements, as well as
the product of the process, all of which are exemplified in the following
detailed disclosure, and the scope of the application of which will be
indicated in the claims.

BRIEF DESCRIPTION OF THE FIGURES

[0016]FIG. 1 is a operations diagram of the process of this invention.

[0017]FIG. 2 is a simplified black box diagram of the process of the
invention.

[0018]FIG. 3 is a diagram that illustrates the operational principles of a
capacitive desalination plant.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0019]The discussion commences at FIG. 1. Coal Bed Methane produced water,
11 from any coal mine, which normally would be deemed a hazardous
material, is collected, and then transported by pipe 13, and pumped 13 as
may be necessary into a Mazzei injector, 15, a multi-patented device made
by the Mazzei Injector Company, LLC of Bakersfield, Calif. and the
mixture is then delivered to a sedimentation tank 23 or to a Couette
reactor/separator 23, for continued simultaneous ozonation and separation
of solids. This Coutette reactor technology is believed to be originally
patented under auspices of the Oak Ridge National Laboratory, Oak Ridge
Tenn.

[0020]Injector 15 has an input line 14 from a plasma chemical reactor 17,
which may hereinafter be called a PCR. These devices are known to the art
from such patents as U.S. Pat. No. 4,013,415 and U.S. Pat. No. 6,846,467
among others. Applicant uses a PCR to generate ozone, which ozone is
delivered by pipe 14 to the Mazzei® injector. In operation the Mazzei
injector creates a vacuum to suck the ozone from the plasma chemical
reactor. This negates the requirement of having to pump ozone to a
reaction zone, as ozone is quite corrosive to piping. In actual
operation, the Mazzei injector draws the ozone into a small pipe for
mixture with a finite amount of water, the concentrated water-ozone mix
is then delivered to the main pipe, usually a 4 inch pipe as opposed to a
1 inch pipe for the initial input. The further diluted ozone-water mix is
then delivered to the sedimentation tank or Couette Reactor/separator 23.

[0021]While there are other means for delivering ozone from its source of
creation, the Mazzei injector creates the most minute micro-bubbles and
is therefore the preferred piece of equipment.

[0022]Here in the diluted ozone water mix, the Ferrous iron with a valance
of plus 2 is oxidized to Ferric iron with a valance of +3. The manganese
ion present as Mn+2 is oxidized to the higher manganic ion with a valance
of +4. These oxidized ions form dissolved or soluble metallo-organic
compounds both stay in solution and for the most part form compounds
which can be separated out. While a Plasma Chemical Reactor is the
preferred apparatus for ozone generation, any apparatus that generates
ozone can be utilized in this reclamation process.

[0023]The sedimentation tank, 23, or an equivalent acting apparatus such
as a cyclonic separator or a Couette reactor/separator, which ever is
used, is generally wider at the top and tapers to a narrower bottom for
ease of removal of solids. The separation means 23--used generically here
for any of the 3 apparatuses--, has two inputs one from the injector for
CBM (coal bed methane) water and one for input from a SAR tank, line 51.
Prior to discussing the SAR tank, it should be pointed out that the
Couette Reactor/separator allows for the use of a lower quantity of ozone
than do the other two separation means. This apparatus offers the
advantage of being a continuous reactor with high throughput and is
compact and easy to use.

[0024]The term SAR will be discussed in further detail infra with respect
to the discussion of the SAR tank 53. The tapering downward shape permits
mass that accumulates due to gravity to collect in a smaller space, thus
rendering it easier to collect. Moist waste product containing ferric
oxide and manganic oxide is removed through a port at the bottom of the
sedimentation tank and is piped via pipes and pump 25 to a conventional
sedimentation pond 53.

[0025]A fluid port connected to pipes and pump 27 delivers the water
containing dissolved solids to a rotating screen filter 29. Micro-screen
rotating drum filters, are an alternative to sand filtration especially
when excessive waste water is a concern, as here. The filtering process
of these rotating screen filters captures particles on a screen fabric
while letting the water pass through. They are designed with few moving
parts to ensure long life and low operational costs, with minimal
maintenance. One brand of such products known to applicant is
Hydrotech®, and another is Orival®.

[0026]The captured solids are moved by pipes and pumps 49 from the
rotating screen filter 29 to the sedimentation pond 53. Note also that
the sedimentation tank 23 also receives fluid from SAR tank 43 via pipe
51,51A to help dilute the water in the sedimentation tank 23, some of
which is exiting port 25 with the solid waste. Note further that water
from the SAR tank 43 also enters the rotating screen filter via pipe line
51,51B near the egress end. See FIG. 1.

[0027]Water exiting the rotating screen filter passes through a gate valve
31 to split the flow to two banks or sets of capacitive desalination
cells. Each bank can easily have from 6 to 10 capacitive desalination
stations, or even more which alternate between an operation cycle and a
cleaning cycle. One such bank is designated 39A and the other 39B in FIG.
1.

[0028]Reference is made to FIG. 3 which sets forth the operating
principles of this technology. The capacitive desalination
technology--(CDT)--works in two half cycles, wherein the pairs of spaced
electrodes are first polarized to separate solids from water, and then
de-polarized to backwash the collected solids away such that the
polarized cycle can commence. In CDT brackish water or other non-potable
water is pumped between pairs of high surface area carbon electrodes,
such as those called aerogels, which electrodes are held at a potential
difference of about 1.3 volts+/-Ions present and other charged particles
such as microorganisms bind to and are retained at the electrode of an
opposing charge. Thus cations, go to the anode, or negative electrode.
Typical ions that can separated in such manner include Ca, Mg, and
Na--calcium, magnesium and sodium respectively.

[0029]The same concept holds true for anions which are negatively charged.
They are attracted to the positive electrode. Typical anions include
chloride, nitrate and silicate, and sulfate ions. This attraction half
cycle is called the active cycle. The ions stick to the electrode plates
and the clarified water passes from the cell. This last activity takes
place through pipes and pumps 41A, and 41B to the SAR tank 43.

[0030]Part of the exiting water also goes via piping 45A and 45B
respectively through valve system 37 back to each cell bank via piping
35B and 35A. See FIG. 1. Fluid from the SAR tank 43 also flows through
the same valve system 37 to the respective cell bank via the same piping
35A and 35B.

[0031]When and as the electrodes have reached near their capacity in ion
content, the applied electrical potential is removed. The ions become
unbound from their respective electrodes, and are flushed out of the cell
during the depolarization cycle by the incoming water entering via piping
35A, 35B, from both the exudate of the respective cell and from the SAR
tank. This concentrated waste product goes back through the valve system
37 to the evaporation pond or other collection location 53. Thus it is
seen that the valve system 37 provides both access and egress from the
CDT cells.

[0032]The discussion now moves to the SAR tank 43 seen in the lower right
corner of FIG. 1. In order to make this coal bed methane potable and
suitable for agriculture, it is necessary to reduce the sodium ion
content dissolved therein. This is because excess sodium in water can
cause the crusting of seed beds, temporary saturation of surface soil
thus preventing permeation of the water, and the sodium can contribute to
increased levels of plant disease, soil erosion, and cause high pH in the
soil and water. Fruits, nuts citrus and avocados are especially sensitive
to high levels of sodium in the water.

[0033]Contrary to popular belief, SAR does NOT stand for sodium anion
reduction. Rather it stands for sodium adsorption ratio. It is an
expression of relative activity of sodium ions in the exchange reactions
with soil. This ratio measures the relative concentration of sodium ion
to calcium and magnesium. SAR=Sodium ion content divided by the square
root of the sum of Ca ion and Mg ion divided by 2. The SAR tank, includes
a packed ion exchange column of calcium carbonate to further reduce the
sodium content as the sodium containing water is passed therethrough. The
operation of SAR tanks is generally well understood by those skilled in
the art.

[0034]It is seen from FIG. 1 that the procedure also includes the steps of
recycling some of the output from one or both of the at least capacitive
desalination cell and some of the output from the S.A.R. tank, back
through a valve system into the at least one desalination cell for cell
cleaning purposes. Some of the output from the S.A.R. tank can also be
sent back to both the sedimentation tank and the filter station, if
desired. Again see FIG. 1.

[0035]Since certain changes may be made in the above process without
departing from the scope of the invention herein involved, it is intended
that all matter contained in the above description and shown in the
accompanying drawings, shall be interpreted as illustrative only and not
in a limiting sense.